Writing in the news: English books becoming less emotional

According to a study referred to in this New York Times article by Jennifer Schuessler, English-language books are becoming less emotional. The only exception: Words relating to fear are on the increase.  The study looked at “broad emotional shifts across decades” and found that “‛happy’ and ‘sad’ periods coincided with historical events.”

Does that mean we’re living in a fearful decade? If we are,  would it be wise for writers to write about fear?